Re: [CAD_CAM_EDM_DRO] Re: over voltage power supply with low voltage servo motors ?

Hi Dave,

I plugged a 24V secondary transformer into the VARIAC. With a bridge rectifier
and a cap on the secondary of the transformer, and starting low on the VARIAC
setting, I brought it up to the initial voltage I wanted to test with.

A switching supply is liable to give you the SAME voltage out, even if you drop
the input voltage down! Many new switchers can work 90 280V or so. That's
where a simple XFMR, bridge and cap can work to advantage. Look for surplus
linear regulated power supplies that have quit working at surplus outlets,
usually the xfmr and cap are OK, the reg circuit is shot, and possibly the
bridge. OR just get the parts. The linear frames are nice, even if you buy
fully functional units. They are often quite cheap surplus.

Alan KM6VV


turbulatordude wrote:

> I need 9 volts or 9.6 volts and have 2 switching power supplies.
>
> for the servo, the transformers, caps and such will be close to $100,
> but a switcher from MPJA is only $29.00 plus a post PS capacitor to
> handle the back EMF.
>
> I do wish I had a simple transformer version....
>
> um... I do have a variac that I could test with. Not as familiar with
> those in application. should I use it directly to get the voltage,
> or power a second stepdown transformer to get the voltage ?
>
> Not enough current to use to run, but enough to test each part
> individually.
>
>
> Dave
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, KM6VV <KM6VV@a...> wrote:
>
>>Dave,
>>
>>Why not just use a VARIAC and a 12 - 24V XFMR LINEAR supply? That's
> what I did this weekend to bring up a new board.
>>
>>Alan KM6VV
>>